Range-finder.



A. A. MIGHELSON.

RANGE FINDER.

APPLICATION FILED $21124, 1912.

1,030,846, PatentedJune 25, 1912.

WMQ

tJNiTED STATES PATENT OFFICE.

ALBERT A. MICHELSON, OF CHICAGO, ILLINOIS.

RANGE-FINDER.

To all whom it may concern.

Be it known that I, ALBERT A. MICHEL- SON, a citizen of the UnitedStates, and a resident of Chicago, county of Cook, and State ofIllinois, have invented certain new and useful Improvements inRange-Finders, of whichthe following is a specification.

The invention relates to range finders and seeks to provide simple andeifective means for quickly determining the range inconnection with tworay receiving or sighting instruments located at the opposite ends of abase line and both rotatable so that they may be directed toward atarget withoutshifting the base line.

The invention consists in the features of improvement hereinafter setforth, illustrated in the preferred form in the accompanying drawingsand more particularly pointed out in the appended claims.

In the drawings, Figure 1 is a plan view indicating the generalconstruction and arrangement of the instruments at the opposite ends ofthe base line. Fig. 2 is a view in elevation of the instrument at onestation and by which the range is indicated. Figs. 3 and 4 indicatev thearrangement of the hair lines in the telescopes at the two stations.

The instruments A and B are located at the opposite ends of the baseline 6. These instruments may be mounted at fixed points on land or atdifferent stations upon a vessel. For accurate determination of therange, it is desirable that the base line he as long as possible and,therefore, that the two instruments be located as far apart asconvenient. The base line Z2 forms one side of a triangle, the other twosides of which meet at the dist-ant target t.

Each station is provided with a ray receiving or sighting instrumentand, in the form shown, telescopes 10 and 11 are employed. Thesetelescopes are arranged to swing upon axes a and b at opposite ends ofthe base line b, as indicated, or at opposite ends of a line parallel tothe base line. The observation telescopes 10 and 11 or like sightingdevices 'in azimuth are rotatable, as stated, about the axes a and b andso that both may be readily directed upon the distant target 25 withoutnecessitating the shift of the base line b which may be fixed, as whenthe instruments are on land, or

shiftable, as when instruments are mounted upon a vessel.

Specification of Letters Patent.

Application filed February 24, 1912.

Patented June 25, '1912. Serial No. 679,600.

The telescope or sighting device 11 at station B is, in the form shown,mounted upon a suitable support 12 which is fixed to a horizontal turntable or worm wheel 13. The latter is mounted upon a shiftablesupporting base 14 to rotate about the axis .7). A screw 15 on a shaft16 is arranged to engage the worm wheel 18. The shaft 16 is mounted, asindicated, in suitable hearings on the base plate 14 and at one end isprovided with a hand wheel 17 by which the worm wheel 13 and telescope11 may be rotated and thus brought to bear upon the target. The turntable is provided with a pointer 18 which is arranged to cooperate witha scale-piece 19 on the base plate 14 to The instrument at the station Ais provided with a similar turn table or worm wheel 13 which isrotatable about the axis a at the end of the base line b and which isdriven, in a similar manner, by a worm 15 on the shaft 16. The turntable 13 is also provided with a pointer 18. and scale 19 to indicatethe zero position of the instrument. The turn table or worm wheel 13' atstation A is provided with a radial arm or member 20 fixed thereto. Inthe zero position of the instrument A this arm is at right angles to thebase line?) and, hence, is parallel to the telescope 11 at station 6when the latter is in zero position. A second, parallel motion arm orlink 21 is mounted on the base plate 14 to swing about an axis 22 andthe ends of the arms 20 and 21 are connected by pivots 23 and 24 to theends of a parallel motion member 25. The arms 20, 21 and the member25are similar to the parts of a parallel ruler, thatis to say, the arms20 and 21 are of the same length and the distance between the pivots 23and 24 is equal to the distance between the axes a and 22 of the arms.These axes are mounted upon a line which, as shown, coincides with thebase line b, or the axes of the arms, if desired, could be arranged on aline parallel to the base line bf'The connecting member 25 is thus atall times maintained parallel to the base line.

The telescope or sighting instrument 10 of instrument A is not fixed tothe turn table or worm wheel 13, but is mounted upon an independentlymovable arm 26.

the range.

This arm is mounted to swing upon an axis which 15 located on a .lmeextending through the axes a and 22 and preferably, as shown, the axis ais common to the arm 20 and the arm 26. a As shown, the arm 26 isprovided The arm 26, which carries the telescope 10,

intersects and is preferably connected to the parallel motion memberbetween the arms or links 20 and 21 to shift therewith, but the arm andtelescope are adjustable relatively to the parallel motion member todetermine In the form shown, the arm 26 is provided at its outer endwith a longitudinal slot 28 and a pivot 29 extending through the slotconnects the arm to a nut 30 which is mounted to slide longitudinally onthe member 25. An adjusting screw, engaging the nut, is rotatablymounted in suitable bearings 82 on the member 25. The screw is heldagainst longitudinal movement relatively to the member 25, and at oneendthe screw is provided with an adjusting wheel 33.

In using the instrument, one operator is located at instrument B and oneor more operators at instrument A. The operators are in telephoniccommunication. The operator at instrument B brings the telescope orsighting device 11 to bear upon some pre determined point of the target,and the operatorof instrument A, or one of the operators at thatinstrument, by means of the hand wheel 17 maintains the parallel motionarms or members 20 and 21 parallel with the telescope 11. The wormwheels and screws of the instruments are identicaland the operator atstation B telephones, from time to time, the number of turns of thescrews necessary to direct the telescope 11 upon a predetermined pointof the target. 'The operator, or one of the operators at station A, bymeans of the wheel 33 maintains the sighting instrument 10 upon the samepredetermined point of the target. Under such circumstances, the axis ofthe parallel mot-ion arm or link 20 will be parallel to the line D fromthe distant target t'to the axis 5, and the member25 will be parallel tothe base line b. The triangle a, t, I) will, therefore, be similar tothe triangle a, 23, 29, and if D is the distance or range to bedetermined, 1' the length of the arm 20, and a the distance between thepivot 23 and the pin 29, then,

sis

and,

the range equals a known con'starit divided,

by the distance so which can be measured. But, .sinceD, and mare theonly variables 1n the equation for determmmg the range, a

scale for measuring the distance a: may be properly graduated to give adirect reading of the range. For this purpose, the parallel motionmember 25 is provided with a scale l 34 and an indicating mark orpointer on the nut 30 cooperates with the scale to give the range. Or,if 'desired,'the' scale Could be associated with the hand wheel33.

Preferably, each of the telescopes 10 and 1 1 is provided with a seriesof vertical, uniformly spaced hair lines, as indicated in Figs. 3 and4:. For convenience, these lines can be numbered. This arrangement wouldmaterially decrease the amount of adjustment of the telescopes orsighting instruments necessary indetermining the range of a movingtarget. The operator at instrument B, instead of continually adjustingthe telescope 11 'to maintain a single hair line upon a predeterminedpoint of the target, could inform the operator at station A when thepredetermined point of'the target is bisected by the difi' erentvertical hair lines of his instrument, and the latter operator, byadusting instrument A until the corresponding lines bisected thepredetermined point of the target, could quickly determine the range. Inthis way with a relatively movable target, the amount of adjustmentnecessary for instrument A is greatly decreased and instrument B needonly be adjusted I when the target has passed out of the field of view.

It is obvious that numerous changes may be made in the details set forthwithout departure from the essentials of the invention 1909. Such anarrangement would obviate the necessity of having an operator at stationB.

I claim as my invention z 1. In range finders, the combination with tworay receiving instruments mounted in azimuth at the opposite ends-of abaseline, of a parallel motion member, and arms whereon said member ismounted having their axes on a line-coincident with or parallel to thebase line, said parallel motion member being associated with one of saidinstruments and cooperating therewith to determine the range,substantially as described.

2. In range finders, the-combination'with two ray recelvmg mstrumentsmounted in azimuth at the opposite ends of a base line, a swingingsupport for one of said instruments, a suitable base whereon saidsupport is mounted, a parallel motion member, and arms pivoted on saidbase and carrying said parallel motion member, said arms and saidswinging instrument support having their axes on a line coincident withor parallel to the base line, and said support being adjustable alongsaid parallel motion member to determine the range, substantially asdescribed.

3. In range finders, the combination with two sighting instrumentsrotatably mounted upon vertical axes at the opposite ends of a baseline, of a swinging support whereon one of said instruments is mounted,a base whereon said support is mounted, a parallel motion member, andsupporting arms therefor pivoted on said base and having their axes onsaid base line, said swinging support intersecting said parallel motionmember and having a pin and slot connection therewith, and means foradjusting said support along said parallel motion member to direct theinstrument thereon upon the target, substantially as described.

4. In range finders, the combination with two sighting instrumentsrotatably mounted upon vertical axes at the opposite ends of a baseline, of a swinging support whereon one of said instruments is mounted,a base whereon said support is mounted, a parallel motion member, andsupporting arms therefor pivoted on said base and having their axes onsaid base line, said swinging support intersecting said parallel mot-ionmember and having a pin and slot connection therewith, means foradjusting said support along said parallel motion member to direct theinstrument on the support toward the target, and a scale associated withsaid adjusting means for indicating the range, substantially asdescribed.

5. In a range finding instrument, the combination with a base, of aparallel motion member, arms carrying said member and pivotally mountedon said base, a support pivoted on said base in line with the axis ofone of said arms and intersecting said parallel mot-ion member, asliding pin connecting said support and said parallel motion member, asighting instrument mounted on said support, a scale on said parallelmotion member cooperating with said sliding pin to determine the range,substantially as described.

6. In a range finding instrument, the combination with a base, of aparallel motion member having parallel arms pivoted to said base, asighting instrument, a supporting arm for said sighting instrumentpivotally mounted on said base with its axes in line with the axes ofsaid parallel arms, a pin slidably mounted on said parallel motionmember and engaging a longitudinal slot in said supporting arm, meansfor adjusting said pin along said parallel motion member, and a scale onsaid member for indicating the extent of adjustment of said pin,substantially as described.

7. In range finders, the combination with two sighting instrumentsrotatably mounted upon vertical axes at the opposite ends of the baseline, of worm wheels and worms for rotating said instruments, one ofsaid instruments being adjustable about its axis independently of theworm wheel therefor, a parallel mot-ion member associated with thelatter instrument and pivotally connected to the worm wheel thereof,means for maintaining said member parallel to the base line and a scalefor indicating the extent of ad justment of said last mentionedinstrument relatively to said parallel motion member, substantially asdescribed.

' ALBERT A. MICHELSON.

Witnesses:

ELEANOR HAGENow, KATHARINE GERLAoH.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. G.

